From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13F23C43441 for ; Mon, 19 Nov 2018 16:39:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C732D20989 for ; Mon, 19 Nov 2018 16:39:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="UpGNSEAx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C732D20989 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732778AbeKTDDn (ORCPT ); Mon, 19 Nov 2018 22:03:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:36414 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731810AbeKTDDm (ORCPT ); Mon, 19 Nov 2018 22:03:42 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D90B5208E3; Mon, 19 Nov 2018 16:39:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542645572; bh=qD/dhIoZ4RM7yvlSCeA2f0zMK4MCnvXkDyentAywsk0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UpGNSEAx/eV+x2KeVD8hncsISYMNNEhTW8ZxX/HuocOIVtC2PUpMdVj+BIe03eWeR j0OSKOyiiAyw1Ihz7lomo1D1aVrbjasUcGuddKX6FRgANv7rM/cYkcrTdAhxFcxadL 9UjqBVILBrYcGkhbwtBtVZiQ2tlKjzxmy//lGti4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Clinton Taylor , Jani Nikula , Ville Syrjala , Daniel Vetter , Lucas De Marchi , Manasi Navare , Alexander Wilson , Rodrigo Vivi Subject: [PATCH 4.19 184/205] drm/i915/dp: Link train Fallback on eDP only if fallback link BW can fit panels native mode Date: Mon, 19 Nov 2018 17:28:11 +0100 Message-Id: <20181119162641.482740014@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162616.586062722@linuxfoundation.org> References: <20181119162616.586062722@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Manasi Navare commit 041444458835d7fb2c9f042598bfe16bf375b15d upstream. This patch fixes the original commit c0cfb10d9e1de49 ("drm/i915/edp: Do not do link training fallback or prune modes on EDP") that causes a blank screen in case of certain eDP panels (Eg: seen on Dell XPS13 9350) where first link training fails and a retraining is required by falling back to lower link rate/lane count. In case of some panels they advertise higher link rate/lane count than whats required for supporting the panel's native mode. But we always link train at highest link rate/lane count for eDP and if that fails we can still fallback to lower link rate/lane count as long as the fallback link BW still fits the native mode to avoid pruning the panel's native mode yet retraining at fallback values to recover from a blank screen. v3: * Add const for fixed_mode (Ville) v2: * Send uevent if link failure on eDP unconditionally Fixes: c0cfb10d9e1d ("drm/i915/edp: Do not do link training fallback or prune modes on EDP") Cc: Clinton Taylor Cc: Jani Nikula Cc: Ville Syrjala Cc: Daniel Vetter Cc: Lucas De Marchi Cc: # v4.17+ Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107489 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105338 Signed-off-by: Manasi Navare Tested-by: Alexander Wilson Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20181009212804.702-1-manasi.d.navare@intel.com (cherry picked from commit 1e712535c51ab025ebc776d4405683d81521996d) Signed-off-by: Rodrigo Vivi Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_dp.c | 30 ++++++++++++++++++++++++++ drivers/gpu/drm/i915/intel_dp_link_training.c | 26 +++++++--------------- 2 files changed, 39 insertions(+), 17 deletions(-) --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -401,6 +401,22 @@ static bool intel_dp_link_params_valid(s return true; } +static bool intel_dp_can_link_train_fallback_for_edp(struct intel_dp *intel_dp, + int link_rate, + uint8_t lane_count) +{ + const struct drm_display_mode *fixed_mode = + intel_dp->attached_connector->panel.fixed_mode; + int mode_rate, max_rate; + + mode_rate = intel_dp_link_required(fixed_mode->clock, 18); + max_rate = intel_dp_max_data_rate(link_rate, lane_count); + if (mode_rate > max_rate) + return false; + + return true; +} + int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, int link_rate, uint8_t lane_count) { @@ -410,9 +426,23 @@ int intel_dp_get_link_train_fallback_val intel_dp->num_common_rates, link_rate); if (index > 0) { + if (intel_dp_is_edp(intel_dp) && + !intel_dp_can_link_train_fallback_for_edp(intel_dp, + intel_dp->common_rates[index - 1], + lane_count)) { + DRM_DEBUG_KMS("Retrying Link training for eDP with same parameters\n"); + return 0; + } intel_dp->max_link_rate = intel_dp->common_rates[index - 1]; intel_dp->max_link_lane_count = lane_count; } else if (lane_count > 1) { + if (intel_dp_is_edp(intel_dp) && + !intel_dp_can_link_train_fallback_for_edp(intel_dp, + intel_dp_max_common_rate(intel_dp), + lane_count >> 1)) { + DRM_DEBUG_KMS("Retrying Link training for eDP with same parameters\n"); + return 0; + } intel_dp->max_link_rate = intel_dp_max_common_rate(intel_dp); intel_dp->max_link_lane_count = lane_count >> 1; } else { --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -352,22 +352,14 @@ intel_dp_start_link_train(struct intel_d return; failure_handling: - /* Dont fallback and prune modes if its eDP */ - if (!intel_dp_is_edp(intel_dp)) { - DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d", - intel_connector->base.base.id, - intel_connector->base.name, - intel_dp->link_rate, intel_dp->lane_count); - if (!intel_dp_get_link_train_fallback_values(intel_dp, - intel_dp->link_rate, - intel_dp->lane_count)) - /* Schedule a Hotplug Uevent to userspace to start modeset */ - schedule_work(&intel_connector->modeset_retry_work); - } else { - DRM_ERROR("[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d", - intel_connector->base.base.id, - intel_connector->base.name, - intel_dp->link_rate, intel_dp->lane_count); - } + DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d", + intel_connector->base.base.id, + intel_connector->base.name, + intel_dp->link_rate, intel_dp->lane_count); + if (!intel_dp_get_link_train_fallback_values(intel_dp, + intel_dp->link_rate, + intel_dp->lane_count)) + /* Schedule a Hotplug Uevent to userspace to start modeset */ + schedule_work(&intel_connector->modeset_retry_work); return; }